Systems, devices, and methods for securely transmitting a security parameter to a computing device

ABSTRACT

Embodiments of the systems, devices, and methods described herein generally facilitate the secure transmittal of security parameters. In accordance with at least one embodiment, a representation of first data comprising a password is generated at the first computing device as an audio signal. The audio signal is transmitted from the first computing device to the second computing device. The password is determined from the audio signal at the second computing device. A key exchange is performed between the first computing device and the second computing device wherein a key is derived at each of the first and second computing devices. In at least one embodiment, one or more security parameters (e.g. one or more public keys) are exchanged between the first and second computing devices, and techniques for securing the exchange of security parameters or authenticating exchanged security parameters are generally disclosed herein.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/434,265, filed Mar. 29, 2012, which is a continuation of U.S. patentapplication Ser. No. 12/420,387, filed Apr. 8, 2009. The entire contentsof U.S. application Ser. No. 12/420,387, and U.S. patent applicationSer. No. 13/434,265 are hereby incorporated by reference.

FIELD

Embodiments described herein relate generally to the transmittal ofsecurity parameters, and more specifically to the secure transmittal ofsecurity parameters between two computing devices.

BACKGROUND

Situations where users of computing devices wish to communicate datapresent a number of challenges.

Some methods for securely transmitting security parameters (e.g. publickeys) between two computing devices may require either manualverification of the security parameter by users of the computing devices(e.g. checking and confirming the public key fingerprint) or a largeamount of infrastructure (e.g. a public key infrastructure to create andmaintain authentic certificates containing public keys).

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of embodiments of the systems and methodsdescribed herein, and to show more clearly how they may be carried intoeffect, reference will be made, by way of example, to the accompanyingdrawings in which:

FIG. 1 is a block diagram of a mobile device in one exampleimplementation;

FIG. 2 is a block diagram of a communication subsystem component of themobile device of FIG. 1;

FIG. 3A is a block diagram of a node of a wireless network;

FIG. 3B is a block diagram illustrating components of an example of awireless router;

FIG. 4 is a block diagram illustrating components of a host system inone example configuration;

FIG. 5 is a block diagram illustrating the secure transmittal ofsecurity parameters from one computing device to another computingdevice in accordance with at least one embodiment;

FIG. 6 is a flowchart illustrating acts of a method of securelytransmitting a security parameter from one computing device to anothercomputing device in accordance with at least one embodiment;

FIG. 7 is a flowchart illustrating acts of a method of securelytransmitting a security parameter from one computing device to anothercomputing device in accordance with at least one other embodiment;

FIG. 8 is an example screen capture of the display of a computing deviceprompting a user with an option to generate either an image (e.g. abarcode) or an e-mail message in accordance with at least oneembodiment;

FIG. 9 is an example screen capture of the display of a computing devicewherein a user has selected an option to generate an image (e.g. abarcode) in accordance with an example embodiment;

FIG. 10 is an example screen capture of the display of a computingdevice as it displays an image (e.g. a barcode) for transmission toanother computing device in accordance with an example embodiment;

FIG. 11 is an example screen capture of the display of a computingdevice prompting a user with an option to receive the transmission of animage (e.g. a barcode) from another computing device in accordance withan example embodiment;

FIG. 12 is an example screen capture of the display of a computingdevice as it instructs a user on how to receive an image (e.g. abarcode) from another computing device in accordance with an exampleembodiment;

FIG. 13 is an example screen capture of the display of a computingdevice upon receiving an image (e.g. a barcode) transmitted from anothercomputing device and upon determining first data from the image (e.g. abarcode) in accordance with an example embodiment; and

FIG. 14 is an example screen capture of the display of a computingdevice wherein a user has selected an option to generate an e-mailmessage in accordance with an example embodiment.

DETAILED DESCRIPTION

Some embodiments of the systems and methods described herein makereference to a mobile device. A mobile device may be a two-waycommunication device with advanced data communication capabilitieshaving the capability to communicate with other computer systems. Amobile device may also include the capability for voice communications.Depending on the functionality provided by a mobile device, it may bereferred to as a data messaging device, a two-way pager, a cellulartelephone with data messaging capabilities, a wireless Internetappliance, or a data communication device (with or without telephonycapabilities), for example. A mobile device may communicate with otherdevices through a network of transceiver stations.

To aid the reader in understanding the structure of a mobile device andhow it communicates with other devices, reference is made to FIGS. 1through 3.

Referring first to FIG. 1, a block diagram of a mobile device in oneexample implementation is shown generally as 100. Mobile device 100comprises a number of components, the controlling component beingmicroprocessor 102. Microprocessor 102 controls the overall operation ofmobile device 100. Communication functions, including data and voicecommunications, may be performed through communication subsystem 104.Communication subsystem 104 may be configured to receive messages fromand send messages to a wireless network 200. In one exampleimplementation of mobile device 100, communication subsystem 104 may beconfigured in accordance with the Global System for Mobile Communication(GSM) and General Packet Radio Services (GPRS) standards. The GSM/GPRSwireless network is used worldwide and it is expected that thesestandards may be supplemented or superseded eventually by Enhanced DataGSM Environment (EDGE) and Universal Mobile Telecommunications Service(UMTS), and Ultra Mobile Broadband (UMB), etc. New standards are stillbeing defined, but it is believed that they will have similarities tothe network behaviour described herein, and it will also be understoodby persons skilled in the art that the embodiments of the presentdisclosure are intended to use any other suitable standards that aredeveloped in the future. The wireless link connecting communicationsubsystem 104 with network 200 represents one or more different RadioFrequency (RF) channels, operating according to defined protocolsspecified for GSM/GPRS communications. With newer network protocols,these channels are capable of supporting both circuit switched voicecommunications and packet switched data communications.

Although the wireless network associated with mobile device 100 is aGSM/GPRS wireless network in one example implementation of mobile device100, other wireless networks may also be associated with mobile device100 in variant implementations. Different types of wireless networksthat may be employed include, for example, data-centric wirelessnetworks, voice-centric wireless networks, and dual-mode networks thatcan support both voice and data communications over the same physicalbase stations. Combined dual-mode networks include, but are not limitedto, Code Division Multiple Access (CDMA) or CDMA2000 networks, GSMIGPRSnetworks (as mentioned above), and future third-generation (3G) networkslike EDGE and UMTS. Some older examples of data-centric networks includethe Mobitex™ Radio Network and the DataTAC™ Radio Network. Examples ofolder voice-centric data networks include Personal Communication Systems(PCS) networks like GSM and Time Division Multiple Access (TDMA)systems. Other network communication technologies that may be employedinclude, for example, Integrated Digital Enhanced Network (iDEN™),Evolution-Data Optimized (EV-DO), and High Speed Packet Access (HSPA),etc.

Microprocessor 102 may also interact with additional subsystems such asa Random Access Memory (RAM) 106, flash memory 108, display 110,auxiliary input/output (I/O) subsystem 112, serial port 114, keyboard116, speaker 118, microphone 120, camera unit 148, short-rangecommunications subsystem 122 and other device subsystems 124.

Some of the subsystems of mobile device 100 performcommunication-related functions, whereas other subsystems may provide“resident” or on-device functions. By way of example, display 110 andkeyboard 116 may be used for both communication-related functions, suchas entering a text message for transmission over network 200, as well asdevice-resident functions such as a calculator or task list. Operatingsystem software used by microprocessor 102 is typically stored in apersistent store such as flash memory 108, which may alternatively be aread-only memory (ROM) or similar storage element (not shown). Thoseskilled in the art will appreciate that the operating system, specificdevice applications, or parts thereof, may be temporarily loaded into avolatile store such as RAM 106.

Mobile device 100 may send and receive communication signals overnetwork 200 after network registration or activation procedures havebeen completed. Network access may be associated with a subscriber oruser of a mobile device 100. To identify a subscriber, mobile device 100may provide for a Subscriber Identity Module (“SIM”) card 126 (or e.g. aUSIM for UMTS, or a CSIM or RUIM for CDMA) to be inserted in a SIMinterface 128 in order to communicate with a network. SIM 126 may be oneexample type of a conventional “smart card” used to identify asubscriber of mobile device 100 and to personalize the mobile device100, among other things. Without SIM 126, mobile device 100 may not befully operational for communication with network 200. By inserting SIM126 into SIM interface 128, a subscriber may access all subscribedservices. Services may include, without limitation: web browsing andmessaging such as e-mail, voice mail, Short Message Service (SMS), andMultimedia Messaging Services (MMS). More advanced services may include,without limitation: point of sale, field service and sales forceautomation. SIM 126 may include a processor and memory for storinginformation. Once SIM 126 is inserted in SIM interface 128, it may becoupled to microprocessor 102. In order to identify the subscriber, SIM126 may contain some user parameters such as an International MobileSubscriber Identity (IMSI). By using SIM 126, a subscriber may notnecessarily be bound by any single physical mobile device. SIM 126 maystore additional subscriber information for a mobile device as well,including datebook (or calendar) information and recent callinformation.

Mobile device 100 may be a battery-powered device and may comprise abattery interface 132 for receiving one or more rechargeable batteries130. Battery interface 132 may be coupled to a regulator (not shown),which assists battery 130 in providing power V+ to mobile device 100.Although current technology makes use of a battery, future technologiessuch as micro fuel cells may provide power to mobile device 100. In someembodiments, mobile device 100 may be solar-powered.

Microprocessor 102, in addition to its operating system functions,enables execution of software applications on mobile device 100. A setof applications that control basic device operations, including data andvoice communication applications, may be installed on mobile device 100during its manufacture. Another application that may be loaded ontomobile device 100 is a personal information manager (PIM). A PIM hasfunctionality to organize and manage data items of interest to asubscriber, such as, but not limited to, e-mail, calendar events, voicemails, appointments, and task items. A PIM application has the abilityto send and receive data items via wireless network 200. PIM data itemsmay be seamlessly integrated, synchronized, and updated via wirelessnetwork 200 with the mobile device subscriber's corresponding data itemsstored and/or associated with a host computer system. This functionalitymay create a mirrored host computer on mobile device 100 with respect tosuch items. This can be particularly advantageous where the hostcomputer system is the mobile device subscriber's office computersystem.

Additional applications may also be loaded onto mobile device 100through network 200, auxiliary I/O subsystem 112, serial port 114,short-range communications subsystem 122, or any other suitablesubsystem 124. This flexibility in application installation increasesthe functionality of mobile device 100 and may provide enhancedon-device functions, communication-related functions, or both. Forexample, secure communication applications may enable electroniccommerce functions and other such financial transactions to be performedusing mobile device 100.

Serial port 114 enables a subscriber to set preferences through anexternal device or software application and extends the capabilities ofmobile device 100 by providing for information or software downloads tomobile device 100 other than through a wireless communication network.The alternate download path may, for example, be used to load anencryption key onto mobile device 100 through a direct and thus reliableand trusted connection to provide secure device communication.

Short-range communications subsystem 122 provides for communicationbetween mobile device 100 and different systems or devices, without theuse of network 200. For example, subsystem 122 may include an infrareddevice and associated circuits and components for short-rangecommunication. Examples of short-range communication include standardsdeveloped by the Infrared Data Association (IrDA), Bluetooth®, and the802.11 family of standards (Wi-Fi®) developed by IEEE.

In use, a received signal such as a text message, an e-mail message, orweb page download is processed by communication subsystem 104 and inputto microprocessor 102. Microprocessor 102 then processes the receivedsignal for output to display 110 or alternatively to auxiliary I/Osubsystem 112. A subscriber may also compose data items, such as e-mailmessages, for example, using keyboard 116 in conjunction with display110 and possibly auxiliary I/O subsystem 112. Auxiliary subsystem 112may include devices such as: a touch screen, mouse, track ball, infraredfingerprint detector, or a roller wheel with dynamic button pressingcapability. Keyboard 116 may comprise an alphanumeric keyboard and/ortelephone-type keypad, for example. A composed item may be transmittedover network 200 through communication subsystem 104.

For voice communications, the overall operation of mobile device 100 maybe substantially similar, except that the received signals may beprocessed and output to speaker 118, and signals for transmission may begenerated by microphone 120. Alternative voice or audio I/O subsystems,such as a voice message recording subsystem, may also be implemented onmobile device 100. Although voice or audio signal output is accomplishedprimarily through speaker 118, display 110 may also be used to provideadditional information such as the identity of a calling party, durationof a voice call, or other voice call related information.

Referring now to FIG. 2, a block diagram of the communication subsystemcomponent 104 of FIG. 1 is shown. Communication subsystem 104 maycomprise a receiver 150, a transmitter 152, one or more embedded orinternal antenna elements 154, 156, Local Oscillators (LOs) 158, and aprocessing module such as a Digital Signal Processor (DSP) 160.

The particular design of communication subsystem 104 may be dependentupon the network 200 in which mobile device 100 is intended to operate;thus, it should be understood that the design illustrated in FIG. 2serves only as one example. Signals received by antenna 154 throughnetwork 200 are input to receiver 150, which may perform such commonreceiver functions as signal amplification, frequency down conversion,filtering, channel selection, and analog-to-digital (A/D) conversion.A/D conversion of a received signal allows more complex communicationfunctions such as demodulation and decoding to be performed in DSP 160.In a similar manner, signals to be transmitted are processed, includingmodulation and encoding, by DSP 160. These DSP-processed signals areinput to transmitter 152 for digital-to-analog (D/A) conversion,frequency up conversion, filtering, amplification and transmission overnetwork 200 via antenna 156. DSP 160 not only processes communicationsignals, but also provides for receiver and transmitter control. Forexample, the gains applied to communication signals in receiver 150 andtransmitter 152 may be adaptively controlled through automatic gaincontrol algorithms implemented in DSP 160.

The wireless link between mobile device 100 and a network 200 maycontain one or more different channels, typically different RF channels,and associated protocols used between mobile device 100 and network 200.A RF channel is generally a limited resource, typically due to limits inoverall bandwidth and limited battery power of mobile device 100.

When mobile device 100 is fully operational, transmitter 152 may betypically keyed or turned on only when it is sending to network 200 andmay otherwise be turned off to conserve resources. Similarly, receiver150 may be periodically turned off to conserve power until it is neededto receive signals or information (if at all) during designated timeperiods.

Referring now to FIG. 3A, a block diagram of a node of a wirelessnetwork is shown as 202. In practice, network 200 comprises one or morenodes 202. Mobile device 100 communicates with a node 202 withinwireless network 200. In the example implementation of FIG. 3A, node 202is configured in accordance with GPRS and GSM technologies; however, inother embodiments, different standards may be implemented as discussedin more detail above. Node 202 includes a base station controller (BSC)204 with an associated tower station 206, a Packet Control Unit (PCU)208 added for GPRS support in GSM, a Mobile Switching Center (MSC) 210,a Home Location Register (HLR) 212, a Visitor Location Registry (VLR)214, a Serving GPRS Support Node (SGSN) 216, a Gateway GPRS Support Node(GGSN) 218, and a Dynamic Host Configuration Protocol (DHCP) server 220.This list of components is not meant to be an exhaustive list of thecomponents of every node 202 within a GSM/GPRS network, but rather alist of components that are commonly used in communications throughnetwork 200.

In a GSM network, MSC 210 is coupled to BSC 204 and to a landlinenetwork, such as a Public Switched Telephone Network (PSTN) 222 tosatisfy circuit switched requirements. The connection through PCU 208,SGSN 216 and GGSN 218 to the public or private network (Internet) 224(also referred to herein generally as a shared network infrastructure)represents the data path for GPRS capable mobile devices. In a GSMnetwork extended with GPRS capabilities, BSC 204 also contains a PacketControl Unit (PCU) 208 that connects to SGSN 216 to controlsegmentation, radio channel allocation and to satisfy packet switchedrequirements. To track mobile device location and availability for bothcircuit switched and packet switched management, HLR 212 is sharedbetween MSC 210 and SGSN 216. Access to VLR 214 is controlled by MSC210.

Station 206 may be a fixed transceiver station. Station 206 and BSC 204together may form the fixed transceiver equipment. The fixed transceiverequipment provides wireless network coverage for a particular coveragearea commonly referred to as a “cell”. The fixed transceiver equipmenttransmits communication signals to and receives communication signalsfrom mobile devices within its cell via station 206. The fixedtransceiver equipment normally performs such functions as modulation andpossibly encoding and/or encryption of signals to be transmitted to themobile device in accordance with particular, usually predetermined,communication protocols and parameters, under control of its controller.The fixed transceiver equipment similarly demodulates and possiblydecodes and decrypts, if necessary, any communication signals receivedfrom mobile device 100 within its cell. Communication protocols andparameters may vary between different nodes. For example, one node mayemploy a different modulation scheme and operate at differentfrequencies than other nodes.

For all mobile devices 100 registered with a specific network, permanentconfiguration data such as a user profile may be stored in HLR 212. HLR212 may also contain location information for each registered mobiledevice and can be queried to determine the current location of a mobiledevice. MSC 210 is responsible for a group of location areas and storesthe data of the mobile devices currently in its area of responsibilityin VLR 214. Further VLR 214 also contains information on mobile devicesthat are visiting other networks. The information in VLR 214 includespart of the permanent mobile device data transmitted from HLR 212 to VLR214 for faster access. By moving additional information from a remoteHLR 212 node to VLR 214, the amount of traffic between these nodes canbe reduced so that voice and data services can be provided with fasterresponse times while requiring less use of computing resources.

SGSN 216 and GGSN 218 are elements that may be added for GPRS support;namely packet switched data support, within GSM. SGSN 216 and MSC 210have similar responsibilities within wireless network 200 by keepingtrack of the location of each mobile device 100. SGSN 216 also performssecurity functions and access control for data traffic on network 200.GGSN 218 provides internetworking connections with external packetswitched networks and connects to one or more SGSNs 216 via an InternetProtocol (IP) backbone network operated within the network 200. Duringnormal operations, a given mobile device 100 performs a “GPRS Attach” toacquire an IP address and to access data services. This normally is notpresent in circuit switched voice channels as Integrated ServicesDigital Network (ISDN) addresses may be generally used for routingincoming and outgoing calls. Currently, GPRS capable networks may useprivate, dynamically assigned IP addresses, thus requiring a DHCP server220 connected to the GGSN 218. There are many mechanisms for dynamic IPassignment, including using a combination of a Remote AuthenticationDial-In User Service (RADIUS) server and DHCP server, for example. Oncethe GPRS Attach is complete, a logical connection is established from amobile device 100, through PCU 208, and SGSN 216 to an Access Point Node(APN) within GGSN 218, for example. The APN represents a logical end ofan IP tunnel that can either access direct Internet compatible servicesor private network connections. The APN also represents a securitymechanism for network 200, insofar as each mobile device 100 must beassigned to one or more APNs and mobile devices 100 cannot generallyexchange data without first performing a GPRS Attach to an APN that ithas been authorized to use. The APN may be considered to be similar toan Internet domain name such as “myconnection.wireless.com”.

Once the GPRS Attach is complete, a tunnel is created and all traffic isexchanged within standard IP packets using any protocol that can besupported in IP packets. This includes tunneling methods such as IP overIP as in the case with some IPSecurity (IPsec) connections used withVirtual Private Networks (VPN). These tunnels are also referred to asPacket Data Protocol (PDP) Contexts and there are a limited number ofthese available in the network 200. To maximize use of the PDP Contexts,network 200 will run an idle timer for each PDP Context to determine ifthere is a lack of activity. When a mobile device 100 is not using itsPDP Context, the PDP Context can be deallocated and the IP addressreturned to the IP address pool managed by DHCP server 220.

Mobile device 100 may communicate with a host system 250 through a node202 of wireless network 200 and a shared network infrastructure 224 suchas a service provider network or the public Internet. Access to the hostsystem may also be provided through one or more routers (e.g. situatedbetween the shared network infrastructure 224 and node 202), such as awireless router illustrated in FIG. 3B.

Referring to FIG. 3B, a number of components of an example of a wirelessrouter 26 are illustrated. It will be understood that wireless router 26may comprise different and/or additional components not shown in FIG.3B.

One component that may be present but not directly part of the wirelessrouter 26 is an Internet firewall 27, which may be off-the-shelf andwould protect the wireless router 26 at a lower IP-layer type protocol.Once through the firewall, the host system 250 may connect to one of aplurality of host interface handlers (HIHs) 30. There can be any numberof HIHs depending on the number of hosts that are configured andrequired in the system. The HIH 30 may use various parts of the database31 to confirm and register the incoming host connection. The known hosts31 a sub-component of the database may provide a way of validating thatthe host is known and marking its state as ‘present’ once the host isconnected and authorized. Once the host connection is established, asecure and authenticated point-to-point communication connection may beready for the exchange of data between the host system 250 or serviceand the wireless router 26. There may be a plurality of suchcommunication connections between the wireless router 26 and a pluralityof host systems 250 (e.g. as identified by 250 a, 250 b, 250 c) orservices.

Another component, which may work closely with the HIH 30 is called thewireless transport handler (WTH) 36. The WTH 36 takes responsibility fordata item transfer to and from the mobile device 100. Depending on theload of traffic, and the number of mobile devices 100 in the system,there may be a plurality of WTH 36 components operating in the system.The network backbone 37, using something like a TIBCO queuing system,combined with the work dispatcher 32, may allow each component of thesystem to scale as large as needed.

The next component is the network interface adapter (NIA) 38, whichcould have a communications link directly to the WTH 36, or the NIA 38could be accessible via the network backbone 37. The NIA 38 may providea direct interface to the wireless network 200 being supported. Sincemany of the current wireless data networks 200 may have uniquecommunication connection requirements, this component can buffer theother wireless router components from many of the specific nuances ofthe particular wireless network it is in communication with. The NIA 38may be used to isolate the WTH 36 from much of the details ofcommunication links and physical interface requirements of each wirelessnetwork 200. There could be any number of wireless networks 200, allwith their own connection methods (e.g. shown as 200 a, 200 b, 200 c).In some cases, a proprietary protocol over X.25 may be employed, in theMobitex or Datatac networks, for example. In other cases, a proprietaryprotocol over TCP/IP may be employed, like in newer version of theDatatac network, for example. In other cases, an IP connection may beemployed, supporting either a TCP or UDP data exchange method, like theCDMA, W-CDMA, and GPRS networks.

To further enhance the wireless router 26 there may be other supportcomponents that could either exist separate, or be built into a singlecomponent. The first of these may be a work dispatcher 32. One of thefunctions of the work dispatcher 32, can be to assign a specific WTH 36to a mobile device 100 so that all data items are routed through thesame WTH 36. If a WTH 36 fails, the work dispatcher 32 can find a newWTH 36 to take its place. Additionally, if one WTH 36 becomes too busyor is handling an undesirably large traffic load, the work dispatcher 32can assign data items that are to be routed to the mobile devices 100 toinstead round robin to multiple WTHs 36. This is one example of how thefault tolerant and scalable system is built, and a fault tolerantqueuing system like TIBCO may solve this problem very easily. In theother direction, the work dispatcher 36 can find the correct HIH 30 toaccept data items from mobile devices 100. Since a host system 250 mayconnect to any HIH 30, the work dispatcher 36 finds the HIH 30 that hasresponsibility for or is associated with the host-router communicationconnection initiated by the correct host system 250, and routes the dataappropriately.

Another component in the wireless router 26 that is shown in theexample, is the peer-to-peer (P2P) messaging component 34. Thiscomponent may provide peer-to-peer message routing facility, which canallow mobile devices 100 to send directly to one or more other mobiledevices 100, e.g. multi-cast messages. The P2P component 34 can performthe functions similar to an Instant Messaging gateway, but in this casefor mobile devices 100. In some networks, where the mobile's identitymight not be static, a mobile device 100 cannot easily send a message toanother mobile device 100. In other networks, SMS (short messageservice) may solve this problem and provides a limited 160 characterdata exchange. The wireless router 26 may have a store and forwardstructure that permits it to offer SMS and wireless messagingsimultaneously to all wireless devices 100.

The wireless router 26, in this example, hosts a peer-to-peer messagingserver 80, which utilizes a PIN-to-PIN protocol 82 and a message cache316, all of which may be considered components of the peer-to-peermessaging component 34. Personal identification numbers (PINs) may beused to address messages, for example. Such a PIN-based messaging systemmay be implemented using a server-based communication infrastructure,such as one that provides email, SMS, voice, Internet and othercommunications. Wireless router 26 may be particularly suitable forhosting a peer-to-peer messaging server 80. In a PIN-based messagingprotocol 82, a message may have associated therewith a PIN correspondingto the mobile device 100 which has sent the message (source) and one ormore destination PINs identifying each intended recipient(destination(s)). When conducting a PIN-to-PIN message exchange, mobiledevices may communicate directly with the wireless router 26 in a clientbased exchange where, similar to other peer-to-peer programs, anintermediate server is not required. Upon obtaining one or morerecipient PINs according to the PIN-to-PIN protocol 82, the wirelessrouter 26 may then route the message to all intended recipientsassociated with devices having such PINs. The wireless router 26typically also provides a delivery confirmation to the original sender,which may or may not be displayed to the user, and the mobile device 100can use an exchange of messages pertaining to in and out of coveragesituations to update presence information on the mobile device 100. Thedestination device can also provide such delivery information. Thewireless router 26 may hold messages until they are successfullydelivered. Alternatively, if delivery cannot be made after a certaintimeout period, the wireless router 26 may provide a response indicatinga failed delivery. The wireless router 26 may choose to expire messageif a certain waiting period lapses. In such cases, the mobile device 100may then choose whether or not to resend the message 8.

Registration and billing are two other components 33. These twocomponents could be separated or merged. Registration may involvekeeping track of all valid mobile devices 100 and tracking theirlocation when they make major wireless network 200 changes. Thesechanges are propagated to the associated database 31 and used by thework dispatcher 32 for important work assignment decisions. For example,if a mobile device 100 travels to another country it might be necessaryto move the responsibility of data item delivery to another WTH 36component. As part of the registration function, the user of the mobiledevice 100 may be provided with added security. Services and mobiledevices must be registered and authenticated before they can exchangedata.

The billing component may keep a running tally of the services andamounts of data exchanged between each host system 250 and each mobiledevice 100. The billing component receives messages via the networkbackbone 37. For example, by using a TIBCO architecture it would bepossible to broadcast billing messages to a group of billing components33. Depending on the load of traffic, multiple billing components 33could be processing and saving the billing information to the database31. Each record could have lots of information pertinent to generatingcomplex and relevant billing information. For example, it might bepossible to save the size of the data exchanged, the time of day, theduration, the type of service access and other key pricing elements.

Referring now to FIG. 4, a block diagram illustrating components of ahost system in one example configuration is shown. Host system 250 willtypically be a corporate office or other local area network (LAN), butmay instead be a home office computer or some other private system, forexample, in variant implementations. In this example shown in FIG. 4,host system 250 is depicted as a LAN of an organization to which a userof mobile device 100 belongs.

LAN 250 comprises a number of network components connected to each otherby LAN connections 260. For instance, a user's desktop computing device(“desktop computer”) 262 a with an accompanying cradle 264 for theuser's mobile device 100 may be situated on LAN 250. Cradle 264 formobile device 100 may be coupled to computer 262 a by a serial or aUniversal Serial Bus (USB) connection, for example. Other user computers262 b are also situated on LAN 250, and each may or may not be equippedwith an accompanying cradle 264 for a mobile device. Cradle 264facilitates the loading of information (e.g. PIM data, private symmetricencryption keys to facilitate secure communications between mobiledevice 100 and LAN 250) from user computer 262 a to mobile device 100,and may be particularly useful for bulk information updates oftenperformed in initializing mobile device 100 for use. The informationdownloaded to mobile device 100 may include S/MIME certificates or PGPkeys used in the exchange of messages.

It will be understood by persons skilled in the art that user computers262 a, 262 b will typically be also connected to other peripheraldevices not explicitly shown in FIG. 4. Furthermore, only a subset ofnetwork components of LAN 250 are shown in FIG. 4 for ease ofexposition, and it will be understood by persons skilled in the art thatLAN 250 will comprise additional components not explicitly shown in FIG.4, for this example configuration. More generally, LAN 250 may representa smaller part of a larger network [not shown] of the organization, andmay comprise different components and/or be arranged in differenttopologies than that shown in the example of FIG. 4.

In this example, mobile device 100 communicates with LAN 250 through anode 202 of wireless network 200 and a shared network infrastructure 224such as a service provider network or the public Internet. Access to LAN250 may be provided through one or more routers [not shown], andcomputing devices of LAN 250 may operate from behind a firewall or proxyserver 266.

In a variant implementation, LAN 250 comprises a wireless VPN router[not shown] to facilitate data exchange between the LAN 250 and mobiledevice 100. The concept of a wireless VPN router is new in the wirelessindustry and implies that a VPN connection can be established directlythrough a specific wireless network to mobile device 100. Thepossibility of using a wireless VPN router has only recently beenavailable and could be used when the new Internet Protocol (IP) Version6 (IPV6) arrives into IP-based wireless networks. This new protocol willprovide enough IP addresses to dedicate an IP address to every mobiledevice, making it possible to push information to a mobile device at anytime. An advantage of using a wireless VPN router is that it could be anoff-the-shelf VPN component, not requiring a separate wireless gatewayand separate wireless infrastructure to be used. A VPN connection mayinclude, for example, a Transmission Control Protocol (TCP)/IP or UserDatagram Protocol (UDP)/IP connection to deliver the messages directlyto mobile device 100 in this variant implementation.

Messages intended for a user of mobile device 100 are initially receivedby a message server 268 of LAN 250. Such messages may originate from anyof a number of sources. For instance, a message may have been sent by asender from a computer 262 b within LAN 250, from a different mobiledevice [not shown] connected to wireless network 200 or to a differentwireless network, or from a different computing device or other devicecapable of sending messages, via the shared network infrastructure 224,and possibly through an application service provider (ASP) or Internetservice provider (ISP), for example.

Message server 268 typically acts as the primary interface for theexchange of messages, particularly e-mail messages, within theorganization and over the shared network infrastructure 224. Each userin the organization that has been set up to send and receive messages istypically associated with a user account managed by message server 268.One example of a message server 268 is a Microsoft Exchange™ Server. Insome implementations, LAN 250 may comprise multiple message servers 268.Message server 268 may also be configured to provide additionalfunctions beyond message management, including the management of dataassociated with calendars and task lists, for example.

When messages are received by message server 268, they are typicallystored in a message store [not explicitly shown], from which messagescan be subsequently retrieved and delivered to users. For instance, ane-mail client application operating on a user's computer 262 a mayrequest the e-mail messages associated with that user's account storedon message server 268. These messages may then typically be retrievedfrom message server 268 and stored locally on computer 262 a.

When operating mobile device 100, the user may wish to have e-mailmessages retrieved for delivery to the mobile device 100. An e-mailclient application operating on mobile device 100 may request messagesassociated with the user's account from message server 268. The e-mailclient may be configured (either by the user or by an administrator,possibly in accordance with an organization's information technology(IT) policy) to make this request at the direction of the user, at somepre-defined time interval, or upon the occurrence of some pre-definedevent. In some implementations, mobile device 100 is assigned its owne-mail address, and messages addressed specifically to mobile device 100may be automatically redirected to mobile device 100 as they arereceived by message server 268.

To facilitate the wireless communication of messages and message-relateddata between mobile device 100 and components of LAN 250, a number ofwireless communications support components 270 may be provided. In thisexample implementation, wireless communications support components 270may comprise a message management server 272, for example. Messagemanagement server 272 may be used to specifically provide support forthe management of messages, such as e-mail messages, that are to behandled by mobile devices. Generally, while messages are still stored onmessage server 268, message management server 272 may be used to controlwhen, if, and how messages should be sent to mobile device 100. Messagemanagement server 272 also facilitates the handling of messages composedon mobile device 100, which are sent to message server 268 forsubsequent delivery.

For example, message management server 272 may: monitor the user's“mailbox” (e.g. the message store associated with the user's account onmessage server 268) for new e-mail messages; apply user-definablefilters to new messages to determine if and how the messages will berelayed to the user's mobile device 100; compress and encrypt newmessages (e.g. using an encryption technique such as Data EncryptionStandard (DES) or Triple DES) and push them to mobile device 100 via theshared network infrastructure 224 and wireless network 200; and receivemessages composed on mobile device 100 (e.g. encrypted using TripleDES), decrypt and decompress the composed messages, re-format thecomposed messages if desired so that they will appear to have originatedfrom the user's computer 262 a, and re-route the composed messages tomessage server 268 for delivery.

Certain properties or restrictions associated with messages that are tobe sent from and/or received by mobile device 100 can be defined (e.g.by an administrator in accordance with IT policy) and enforced bymessage management server 272. These may include whether mobile device100 may receive encrypted and/or signed messages, minimum encryption keysizes, whether outgoing messages must be encrypted and/or signed, andwhether copies of all secure messages sent from mobile device 100 are tobe sent to a pre-defined copy address, for example.

Message management server 272 may also be configured to provide othercontrol functions, such as only pushing certain message information orpre-defined portions (e.g. “blocks”) of a message stored on messageserver 268 to mobile device 100. For example, when a message isinitially retrieved by mobile device 100 from message server 268,message management server 272 is configured to push only the first partof a message to mobile device 100, with the part being of a pre-definedsize (e.g. 2 KB). The user can then request more of the message, to bedelivered in similar-sized blocks by message management server 272 tomobile device 100, possibly up to a maximum pre-defined message size.

Accordingly, message management server 272 facilitates better controlover the type of data and the amount of data that is communicated tomobile device 100, and can help to minimize potential waste of bandwidthor other resources.

It will be understood by persons skilled in the art that messagemanagement server 272 need not be implemented on a separate physicalserver in LAN 250 or other network. For example, some or all of thefunctions associated with message management server 272 may beintegrated with message server 268, or some other server in LAN 250.Furthermore, LAN 250 may comprise multiple message management servers272, particularly in variant implementations where a large number ofmobile devices are supported.

While Simple Mail Transfer Protocol (SMTP), RFC822 headers, andMultipurpose Internet Mail Extensions (MIME) body parts may be used todefine the format of a typical e-mail message not requiring encoding,Secure/MIME (S/MIME), a version of the MIME protocol, may be used in thecommunication of encoded messages (i.e. in secure messagingapplications). S/MIME enables end-to-end authentication andconfidentiality, and provides data integrity and privacy from the timean originator of a message sends a message until it is decoded and readby the message recipient. Other standards and protocols may be employedto facilitate secure message communication, such as Pretty Good Privacy™(PGP) and variants of PGP such as OpenPGP, for example. It will beunderstood that where reference is generally made to “PGP” herein, theterm is intended to encompass any of a number of variant implementationsbased on the more general PGP scheme.

Secure messaging protocols such as S/MIME and PGP-based protocols relyon public and private encryption keys to provide confidentiality andintegrity. Data encoded using a private key of a private key/public keypair can only be decoded using the corresponding public key of the pair,and data encoded using a public key of a private key/public key pair canonly be decoded using the corresponding private key of the pair. It isintended that private key information never be made public, whereaspublic key information is shared.

For example, if a sender wishes to send message data to a recipient inencrypted form, the recipient's public key is used to encrypt themessage data, which can then be decrypted only using the recipient'sprivate key. Alternatively, in some encoding techniques, a one-timesession key is generated and used to encrypt the message data, typicallywith a symmetric encryption technique (e.g. Triple DES). The session keyis then encrypted using the recipient's public key (e.g. with a publickey encryption algorithm such as RSA), which can then be decrypted onlyusing the recipient's private key. The decrypted session key can then beused to decrypt the encrypted message data. The message header maycomprise data specifying the particular encryption scheme that must beused to decrypt the encrypted message data. Other encryption techniquesbased on public key cryptography may be used in variant implementations.However, in each of these cases, only the recipient's private key may beused to facilitate successful decryption of the encrypted message data,and in this way, the confidentiality of that data can be maintained.

As a further example, a sender may sign message data using a digitalsignature. A digital signature generally comprises a digest of themessage data being signed (e.g. a hash of the message data being signed)encoded using the sender's private key, which can then be appended tothe outgoing message. To verify the digital signature when received, therecipient uses the same technique as the sender (e.g. using the samestandard hash algorithm) to obtain a digest of the received messagedata. The recipient also uses the sender's public key to decode thedigital signature, in order to obtain what should be a matching digestfor the received message data. If the digests of the received message donot match, this suggests that either the message data was changed duringtransport and/or the message data did not originate from the senderwhose public key was used for verification. Digital signature algorithmsare designed in such a way that only someone with knowledge of thesender's private key should be able to encode a digital signature thatthe recipient will decode correctly using the sender's public key.Therefore, by verifying a digital signature in this way, authenticationof the sender and message integrity can be maintained.

When reference is made to the application of encoding to message data,this means that the message data is encoded using an encoding technique.As noted above, an act of encoding message data may include eitherencrypting the message data or signing the message data. As used in thisdisclosure, “signed and/or encrypted” means signed or encrypted or both.

In S/MIME, the authenticity of public keys used in these operations maybe validated using certificates. A certificate is a digital documentissued, for example, by a certificate authority (CA). Certificates areused to authenticate the association between users and their publickeys, and essentially, provides a level of trust in the authenticity ofthe users' public keys. Certificates contain information about thecertificate holder, with certificate contents typically formatted inaccordance with an accepted standard (e.g. X.509). The certificates aretypically digitally signed by the certificate authority.

In PGP-based systems, a PGP key is used, which is like an S/MIMEcertificate in that it contains public information including a publickey and information on the key holder or owner. Unlike S/MIMEcertificates, however, PGP keys are not generally issued by acertificate authority, and the level of trust in the authenticity of aPGP key typically requires verifying that a trusted individual hasvouched for the authenticity of a given PGP key.

Standard e-mail security protocols typically facilitate secure messagetransmission between non-mobile computing devices (e.g. computers 262 a,262 b of FIG. 4; remote desktop devices). In order that signed messagesreceived from senders may be read from mobile device 100 and thatencrypted messages be sent from mobile device 100, mobile device 100 maybe configured to store public keys (e.g. in S/MIME certificates, PGPkeys) of other individuals. Keys stored on a user's computer 262 a maybe downloaded from computer 262 a to mobile device 100 through cradle264, for example.

Mobile device 100 may also be configured to store the private key of thepublic key/private key pair associated with the user, so that the userof mobile device 100 can sign outgoing messages composed on mobiledevice 100, and decrypt messages sent to the user encrypted with theuser's public key. The private key may be downloaded to mobile device100 from the user's computer 262 a through cradle 264, for example. Theprivate key may be exchanged between the computer 262 a and mobiledevice 100 so that the user may share one identity and one method foraccessing messages.

User computers 262 a, 262 b can obtain S/MIME certificates and PGP keysfrom a number of sources, for storage on computers 262 a, 262 b and/ormobile devices (e.g. mobile device 100) in a key store, for example. Thesources of these certificates and keys may be private (e.g. dedicatedfor use within an organization) or public, may reside locally orremotely, and may be accessible from within an organization's privatenetwork or through the Internet, for example. In the example shown inFIG. 4, multiple public key infrastructure (PKI) servers 280 associatedwith the organization reside on LAN 250. PKI servers 280 include a CAserver 282 that may be used for issuing S/MIME certificates, aLightweight Directory Access Protocol (LDAP) server 284 that may be usedto search for and download S/MIME certificates and/or PGP keys (e.g. forindividuals within the organization), and an Online Certificate StatusProtocol (OCSP) server 286 that may be used to verify the revocationstatus of S/MIME certificates, for example.

Certificates and/or PGP keys may be retrieved from LDAP server 284 by auser computer 262 a, for example, to be downloaded to mobile device 100via cradle 264. However, in a variant implementation, LDAP server 284may be accessed directly (i.e. “over the air” in this context) by mobiledevice 100, and mobile device 100 may search for and retrieve individualcertificates and PGP keys through a mobile data server 288. Similarly,mobile data server 288 may be configured to allow mobile device 100 todirectly query OCSP server 286 to verify the revocation status of S/MIMEcertificates.

In variant implementations, only selected PKI servers 280 may be madeaccessible to mobile devices (e.g. allowing certificates to bedownloaded only from a user's computer 262 a, 262 b, while allowing therevocation status of certificates to be checked from mobile device 100).

In variant implementations, certain PKI servers 280 may be madeaccessible only to mobile devices registered to particular users, asspecified by an IT administrator, possibly in accordance with an ITpolicy, for example.

Other sources of S/MIME certificates and PGP keys [not shown] mayinclude a Windows certificate or key store, another secure certificateor key store on or outside LAN 250, and smart cards, for example.

Situations where users of computing devices wish to communicate datapresent a number of challenges. A primary concern is the security of thecommunication, which may often be wireless. Specifically of concern isthe authenticity and confidentiality of the data being communicated asan attacker within the transmission range of the wireless communicationchannel may easily tamper with or monitor the data being communicated.Some methods for securely transmitting security parameters (e.g. publickeys) between two computing devices may require either manualverification of the security parameter by users of the computing devices(e.g. checking and confirming the public key fingerprint) or a largeamount of infrastructure (e.g. a public key infrastructure to create andmaintain authentic certificates containing public keys).

Embodiments of the systems, devices, and methods described hereingenerally facilitate the secure transmittal of security parameters fromone computing device to another computing device.

In one broad aspect, there is provided a system, device, and method oftransmitting one or more security parameters from a first computingdevice to a second computing device, the method performed at the firstcomputing device, the method comprising: generating an image or audiosignal for transmission to the second computing device, wherein theimage or audio signal is a representation of first data, the first datacomprising a password, wherein the password is not derived from the oneor more security parameters; transmitting the image or audio signal tothe second computing device at which the password is determinable fromthe image or audio signal; performing a key exchange with the secondcomputing device over a communication channel between the first andsecond computing devices, wherein second data is exchanged between thefirst and second computing devices in accordance with a key exchangeprotocol, such that an encryption key is derived at each of the firstand second computing devices using the password; encrypting the one ormore security parameters with the encryption key or a session keyderived from the encryption key; and transmitting the encrypted one ormore security parameters to the second computing device. In someembodiments, the method performed at the first computing device furthercomprises receiving one or more encrypted second security parametersfrom the second computing device, and decrypting the one or moreencrypted second security parameters using the encryption key or asession key derived from the encryption key.

In another broad aspect, there is provided a system, device, and methodof transmitting one or more security parameters from a first computingdevice to a second computing device, the method performed at the firstcomputing device, the method comprising: generating an image or audiosignal for transmission to the second computing device, wherein theimage or audio signal is a representation of first data, the first datacomprising a password, wherein the password is not derived from the oneor more security parameters; transmitting the image or audio signal tothe second computing device at which the password is determinable fromthe image or audio signal; and performing a key exchange with the secondcomputing device over a communication channel between the first andsecond computing devices, wherein second data is exchanged between thefirst and second computing devices in accordance with a key exchangeprotocol, such that a key is derived at each of the first and secondcomputing devices using the password, and wherein the one or moresecurity parameters is transmitted to the second computing device duringthe key exchange; wherein said performing further comprises computing aconfirmation value based on at least the one or more securityparameters, and using the key derived at the first computing device, andtransmitting the confirmation value to the second computing device,wherein the one or more security parameters are authenticated when theconfirmation value is successfully verified at the second computingdevice. In some embodiments, the confirmation value comprises akeyed-hash message authentication code. In some embodiments, the methodperformed at the first computing device further comprises receiving oneor more second security parameters from the second computing device,receiving a second confirmation value from the second computing device,and verifying the second confirmation value.

In some embodiments, said transmitting the image or audio signal to thesecond computing device is performed when the first and second computingdevices are in close physical proximity.

In some embodiments, the one or more security parameters comprise one ormore public keys stored on the first computing device. For example, theone or more public keys may comprise a first public key usable toencrypt messages to a user of the first computing device, and a secondpublic key usable to verify digital signatures of messages digitallysigned at the first computing device.

In some embodiments, the key exchange protocol comprises a SimplePassword Exponential Key Exchange (SPEKE) protocol.

In some embodiments, the image comprises a barcode. In some embodiments,at the transmitting, the image is transmitted via a display of the firstcomputing device.

In some embodiments, the audio signal comprises a plurality of audiotones. In some embodiments, at the transmitting, the audio signal istransmitted via a speaker of the first computing device. In someembodiments, at the transmitting, the audio signal is transmitted via achannel established during a phone call between the first computingdevice and the second computing device.

In some embodiments, the first data further comprises routing dataassociated with the first computing device. In at least one embodiment,the routing data associated with the first computing device comprises aPIN associated with the first computing device, and wherein thecommunication channel between the first and second computing devicescomprises a PIN-to-PIN channel.

In some embodiments, the method performed at the first computing devicefurther comprises generating the password, wherein the password isgenerated as a random number or string. In at least one embodiment, thepassword is generated for a single instance of said generating the imageor audio signal.

In some embodiments, at least one computing device selected from thefollowing group comprises a mobile device: the first computing device,and the second computing device.

In another broad aspect, there is provided a system, device, and methodof transmitting one or more security parameters to a first computingdevice from a second computing device, the method performed at thesecond computing device, the method comprising: receiving an image oraudio signal, wherein the image or audio signal is a representation offirst data, the first data comprising a password, wherein the passwordis not derived from a security parameter stored on the first computingdevice; determining the password from the image or audio signal;performing a key exchange with the first computing device over acommunication channel between the first and second computing devices,wherein second data is exchanged between the first and second computingdevices in accordance with a key exchange protocol, such that anencryption key is derived at each of the first and second computingdevices using the password; encrypting the one or more securityparameters with the encryption key or a session key derived from theencryption key; and transmitting the encrypted one or more securityparameters to the first computing device. In some embodiments, themethod performed at the second computing device further comprisesreceiving one or more encrypted second security parameters from thefirst computing device, and decrypting the one or more encrypted secondsecurity parameters using the encryption key or a session key derivedfrom the encryption key.

In another broad aspect, there is provided a system, device, and methodof transmitting one or more security parameters to a first computingdevice from a second computing device, the method performed at thesecond computing device, the method comprising: receiving an image oraudio signal, wherein the image or audio signal is a representation offirst data, the first data comprising a password, wherein the passwordis not derived from a security parameter stored on the first computingdevice; determining the password from the image or audio signal; andperforming a key exchange with the first computing device over acommunication channel between the first and second computing devices,wherein second data is exchanged between the first and second computingdevices in accordance with a key exchange protocol, such that a key isderived at each of the first and second computing devices using thepassword, and wherein the one or more security parameters is transmittedto the first computing device during the key exchange; wherein saidperforming further comprises computing a confirmation value based on atleast the one or more security parameters, and using the key derived atthe second computing device, and transmitting the confirmation value tothe first computing device, wherein the one or more security parametersare authenticated when the confirmation value is successfully verifiedat the first computing device. In some embodiments, the confirmationvalue comprises a keyed-hash message authentication code. In someembodiments, the method performed at the second computing device furthercomprises receiving one or more second security parameters from thefirst computing device, receiving a second confirmation value from thefirst computing device, and verifying the second confirmation value.

In some embodiments, said receiving the image or audio signal isperformed when the first and second computing devices are in closephysical proximity.

In some embodiments, the one or more security parameters comprise one ormore public keys stored on the second computing device. For example, theone or more public keys may comprise a first public key usable toencrypt messages to a user of the second computing device, and a secondpublic key usable to verify digital signatures of messages digitallysigned at the second computing device.

In some embodiments, the key exchange protocol comprises a SPEKEprotocol.

In some embodiments, the image comprises a barcode. In some embodiments,at the receiving, the image is received via a camera of the secondcomputing device, wherein the camera is configured to process the imageafter being displayed on a display of the first computing device.

In some embodiments, the audio signal comprises a plurality of audiotones. In some embodiments, at the receiving, the audio signal isreceived via a microphone of the second computing device, wherein themicrophone is configured to receive the audio signal after being outputon a speaker of the first computing device. In some embodiments, at thereceiving, the audio signal is received via a channel established duringa phone call between the first computing device and the second computingdevice.

In some embodiments, the first data further comprises routing dataassociated with the first computing device. In some embodiments, themethod performed at the second computing device further comprisesestablishing the communication channel by initiating contact with thefirst computing device using the routing data. In at least oneembodiment, the routing data comprises a PIN associated with the firstcomputing device, and wherein the communication channel between thefirst and second computing devices comprises a PIN-to-PIN channel.

In some embodiments, the password comprises a random number or string.

In some embodiments, at least one computing device selected from thefollowing group comprises a mobile device: the first computing device,and the second computing device.

These and other aspects and features of various embodiments will bedescribed in greater detail below.

Reference is first made to FIG. 5, wherein a block diagram 500illustrating the secure transmittal of security parameters from onecomputing device to another computing device is shown, in accordancewith at least one embodiment.

A first computing device, such as a mobile device (e.g. mobile device100 of FIG. 1 represented as mobile device 100 a), begins bycommunicating a password 510 to a second computing device, such as amobile device (e.g. mobile device 100 of FIG. 1 represented as mobiledevice 100 b). An out-of-band communication path may be used forcommunicating the password between the two computing devices to providegreater security. Once both computing devices have the password, a keyexchange may then be performed between the first computing device andthe second computing device over a communication channel between the twocomputing devices, which may be different from the path used tocommunicate the password, in accordance with a key exchange protocol520.

In this embodiment, as part of the key exchange protocol 520, anencryption key is derived at each of the first computing device and thesecond computing device using password 510. The encryption key or asession key derived from the encryption key 530 a, 530 b, may then beused to encrypt one or more security parameters (e.g. one or more publickeys) or other data to be communicated, thereby establishing anencrypted session 540 over the communication channel between the twocomputing devices.

The secure transmittal of security parameters from one computing deviceto another computing device in accordance with at least one embodimentwill be described in further detail below.

Referring to FIG. 6, a flowchart illustrating acts of a method 600 ofsecurely transmitting a security parameter from one computing device toanother computing device (e.g. as previously described with reference toFIG. 5) is shown, in accordance with at least one embodiment.

In the example embodiments described herein, for illustrative purposes,it is assumed that a first computing device, such as a mobile device(e.g. mobile device 100 of FIG. 1 represented as mobile device 100 a),initiates the transmittal of security parameters. However, personsskilled in the art will appreciate that another computing device, suchas a different mobile device (e.g. mobile device 100 of FIG. 1represented as mobile device 100 b), may initiate the transmittal ofsecurity parameters and, therefore, the acts of method 600 performed atthe first computing device may alternatively be performed by a differentcomputing device.

In at least one embodiment, at least some of the acts of method 600 areperformed by a processor executing an application (e.g. comprising oneor more application modules) residing on a computing device, such as amobile device (e.g. mobile device 100 of FIG. 1). In variantembodiments, the application may reside on a computing device other thana mobile device.

At 605, a password is optionally generated at the first computingdevice. The password may comprise a number, an alphanumeric string (e.g.comprising letters, numbers, and/or symbols), or data in some othersuitable format.

The password may be manually generated (e.g. entered as user input in auser interface by a user of the first computing device), or it may berandomly generated (e.g. by a random password generator). In someembodiments, the password may comprise, for example, 32-bits of randomlygenerated data. The use of randomly generated passwords may provide foradded security over the use of manually generated passwords, as randomlygenerated passwords may typically be more cryptographically complex thanmanually generated passwords. For example, a random password generatorcould be configured to generate a random password comprising acombination of lower and upper case letters, numbers and punctuationsymbols which would typically have a higher strength (i.e. higherinformation entropy) than a manually generated password and may be moredifficult for an attacker to try and guess than a manually generatedpassword.

The password may be a password generated specifically for this instance(e.g. this may be referred to as a “short-term” or “ephemeral” password)or it may be a password that is also used for some other purpose (e.g.this may be referred to as a “long-term” password). Unlike long-termpasswords that may be repeatedly used (e.g. for some other purpose suchas user authentication), a short-term password may be generated afreshfor each instance in which a computing device is to initiate acts of amethod for securely transmitting a security parameter to anothercomputing device, in accordance with an embodiment described herein. Ascompared with long-term passwords, short-term passwords may prevent anattacker from using the previous communication history of a computingdevice to reconstruct the password, since the password is generatedafresh for each new instance. Furthermore, since short-term passwordsare generated afresh for each new instance, the password will nottypically be pre-stored on the computing device (e.g. in a non-volatilememory). This may prevent an attacker from hacking into the computingdevice to obtain the password.

At 610, an image or audio signal is generated at the first computingdevice for transmission to the second computing device at 615, whereinthe image or audio signal is a representation of first data, the firstdata comprising a password (e.g. the password generated at 605).

In at least one embodiment, the password is not derived from a securityparameter (e.g. a public key) associated with a user of the firstcomputing device (e.g. the password is not one of the securityparameters itself or a hash thereof). Put another way, the password andthe one or more security parameters are independent of each other. Inthese embodiments, the present inventors recognized that it may not bedesirable to use a password that is derived from a security parameter ifenhanced security is desirable.

By not communicating data initially that is related to a securityparameter (e.g. a public key) of the first computing device, this mightadd an additional layer of security and provide other benefits. Apotential disadvantage of transmitting a security parameter is that anattacker can intercept the communication and obtain the securityparameter. A potential disadvantage of transmitting a hash of a securityparameter is that an attacker who intercepts the communication andobtains the hash of the security parameter might try all possibilitiesof the security parameter and compare each guess with the hash in orderto reconstruct the security parameter. Moreover, another potentialdisadvantage of transmitting a security parameter or hash thereofrelates to the resultant size of the binary representation of thesecurity parameter or hash thereof that is to be communicated. Forexample, a binary representation of a 512-bit elliptic curve public keymay require about 66 bytes. Persons skilled in the art will appreciatethat a password may typically be generated as one that is shorter inlength than a security parameter (e.g. a public key) or hash thereof,and therefore, less data would need to be transmitted by the firstcomputing device to the second computing device. Transmission of a shortpassword may also consume less computing resources (e.g. bandwidth,time, processing power, etc.) than transmission of a security parameteror hash thereof, which may be particularly beneficial when, for example,the first computing device (and/or the second computing device)comprises a mobile device.

In at least one embodiment, each of one or more security parameters(e.g. one or more public keys) associated with a user of either thefirst computing device or the second computing device is not derivablefrom the password. Persons skilled in the art will appreciate that inorder for a security parameter (e.g. a public key) to be derivable froma password, the password would need to be more complex than the securityparameter. By having the security parameter not be derivable from thepassword, this allows for the use of a smaller, perhapscryptographically weaker, password to bootstrap into a largercryptographically stronger encryption key.

First data may additionally comprise routing data associated with thefirst computing device. The routing data may be such data thatidentifies a computing device, so that it may be contacted by anothercomputing device to establish a communication channel.

In at least some embodiments, the routing data associated with the firstcomputing device may comprise a PIN associated with the first computingdevice. For example, a PIN is typically a unique personal identificationnumber identifying a particular computing device. The PIN may beassigned at the time of manufacture, for example. In other exampleembodiments, the routing data may comprise an IP address and portnumber, or MAC address and subnet mask, or Bluetooth device address, orphone number, or SMS address, for example. The PIN may comprise 8hexadecimal-ASCII characters, for example.

First data may also optionally comprise additional identifyinginformation of the first computing device or a user thereof. Forexample, such identifying information may include, but is not limitedto, the name of the user of the first computing device, the name of agroup of which the user of the first computing device is a member and isseeking to invite the user of the second computing device to join, thetype of the group (e.g. “friend”, “family”, or “work”), a uniqueidentifier for the particular key exchange request (e.g. as initiated at615), or a timestamp or expiry data (e.g. to indicate when a keyexchange must be completed by), or some combination of the above, forexample.

In at least one embodiment, the image may comprise a barcode that is arepresentation of first data (e.g. the password generated at 605), forexample. A barcode is a visual representation of information, as knownin the art. For example, a barcode may comprise a 1-dimensional barcoderepresented by a series of lines of varying widths and spacing. As afurther example, barcode may comprise a 2-dimensional barcoderepresented by squares, dots, hexagons or other geometric patterns. Insome embodiments, the barcode may be a black and white barcode. In otherembodiments, the barcode may be a color barcode.

In at least one embodiment, the audio signal may comprise a plurality ofaudio tones that is a representation of first data, for example. Theplurality of audio tones may comprise a Dual Tone Multiple Frequency(DTMF) sequence, for example.

In some embodiments, the generation of the image or audio signal at 610may be made based on user input provided via a user interface, in whichthe user of the first computing device may be presented with a dialogbox prompting him or her to generate the image or audio signal.

At 615, the image or audio signal generated at 610 is transmitted to thesecond computing device. At 620, the image or audio signal (whichcomprises a representation of first data, the first data comprising, forexample, a password and may additionally comprise routing data and/orother identifying information) transmitted from the first computingdevice at 615 is received at the second computing device.

In one embodiment, the image may be transmitted via a display associatedwith the first computing device at 615. The display may either reside onthe first computing device itself or may be a separate device coupled tothe first computing device. The image may be received via a camera orother optical sensing device associated with the second computing deviceat 620. The camera or other optical sensing device may either reside onthe second computing device itself or may be a separate device coupledto the second computing device. In this embodiment, the camera or otheroptical sensing device is configured to process the image (e.g.photograph the image or scan the image) transmitted from the firstcomputing device, the image being captured after the image is displayedon the display associated with the first computing device.

Persons skilled in the art will appreciate that the image may betransmitted and received using other means in variant embodiments. Forexample, the image may be transmitted and received as an image filethrough a wired connection established between the first computingdevice and the second computing device. As a further example, the imagemay be transmitted as a printout to a printer, wherein the printer mayeither reside on the first computing device itself or may be a separatedevice coupled to the first computing device. The image may then bereceived by the second computing device through a scanner that scans theimage, wherein the scanner may either reside on the second computingdevice itself or may be a separate device coupled to the secondcomputing device.

The audio signal may be transmitted via a speaker (or e.g. an earpiece)associated with the first computing device at 615, wherein the speakermay either reside on the first computing device itself or may be aseparate device coupled to the first computing device. The audio signalmay be received via a microphone associated with the second computingdevice at 620, wherein the microphone may either reside on the secondcomputing device itself or may be a separate device coupled to thesecond computing device, and the microphone is configured to process theaudio signal (e.g. record the audio signal) transmitted from the firstcomputing device (e.g. the audio signal being captured after the audiosignal is played on the speaker associated with the first computingdevice).

Persons skilled in the art will appreciate that the audio signal may betransmitted and received using other means in variant embodiments. Forexample, the audio signal may be transmitted and received as an audiofile through a wired connection established between the first computingdevice and the second computing device. As a further example, the audiosignal may be transmitted through a phone call (e.g. a voice call) overa channel established between the first computing device and the secondcomputing device, although this embodiment may provide less securitythan that provided by other embodiments described herein depending onwhether the channel is secure from eavesdropping.

In some embodiments, the first computing device may be in close physicalproximity to the second computing device when the image or audio signalis to be transmitted. By transmitting and receiving the image or audiosignal when the first computing device and second computing device arein close physical proximity to each other, and representing first datain a form that requires the two computing devices to be in closephysical proximity to one another in order for the first data to besuccessfully transmitted, an added layer of security may be provided.For instance, the users of both computing devices can better ensure thatthey are communicating with each other's computing device only, and notthe computing device of an attacker.

For example, the user of the first computing device can better ensurethat the intended recipient, the user of the second computing device,has received the image or audio signal (e.g. the acts of a method inaccordance with an embodiment described herein may be initiated when theuser of the first and second computing devices are “face-to-face”), andreduce the risk that the image or audio signal will be unknowinglyintercepted. Similarly, the user of the second computing device canensure that the image or audio signal is received from the intendedsender, the user of the first computing device, and not from thecomputing device of an attacker posing as the user of the firstcomputing device. Accordingly, authenticity and confidentiality of thepassword can be generally maintained, as the authenticity andconfidentiality of the image or audio signal that is a representation offirst data comprising the password can be maintained.

Where the password, for example, is represented in an image that isbeing transmitted and received, the user of the first computing deviceand the user of the second computing device can ensure that there is noone else (i.e. a possible attacker) within a line of sight of the imageas it is transmitted (e.g. via a display associated with the firstcomputing device) and received (e.g. via a camera associated with thesecond computing device).

Where the password, for example, is represented in an image that isbeing transmitted and received, two computing devices may be in closephysical proximity when, for example, they are at a sufficient distancesuch that when the image is transmitted by one computing device (e.g.via a display), it may be received at the other computing device (e.g.via a camera), and processed by the other computing device to determinethe first data without error. For example, a greater distance betweenthe two computing devices may be accommodated where the displayassociated with the first computing is larger, and/or where the cameraassociated with the second computing device is capable of capturingimages accurately at a greater distance.

As another example, where the password, for example, is represented asan audio signal that is being transmitted and received, the user of thefirst computing device and the user of the second computing device canensure that there is no one else (i.e. a possible attacker) that maypotentially eavesdrop on the audio signal as it is transmitted (e.g. viaa speaker associated with the first computing device) and received (e.g.via a microphone associated with the second computing device).

Where the password, for example, is represented in an audio signal thatis transmitted and received, two computing devices may be in closephysical proximity when, for example, they are at a sufficient distancesuch that when the audio signal is transmitted by one computing device(e.g. via a speaker), it may be received at the other computing device(e.g. via a microphone), and processed by the other computing device todetermine the first data without error. For example, a greater distancebetween the two computing devices may be accommodated where the speakerassociated with the first computing device provides greateramplification, and/or where the microphone associated with the secondcomputing device is more sensitive.

By transmitting and receiving the image or audio signal in the mannerdescribed above, extensive user involvement need not be required. Theuser of the first computing device need not manually enter informationabout the second computing device or a user thereof in order to transmitthe image or audio signal. For example, the user of the first computingdevice need not manually enter routing data associated with the secondcomputing device to establish a communication channel in order totransmit the image or audio signal. Moreover, the user of the secondcomputing device need not manually type the password into his or hercomputing device in at least one embodiment. In order to transmit theimage or audio signal, the first computing device may be simply directedby the user to display the image, for example, or play the audio signal,for example. The first computing device may be configured to generate atleast some or all of the first data, and represent it in the form of theimage or audio signal, automatically in response to the user direction.

Moreover, by transmitting and receiving an image or audio using anout-of-band communication path, security may be enhanced. Bytransmitting a password in the form of an image or audio signal, thepassword, as represented by the image or audio signal, may be utilizedby both computing devices to bootstrap to a larger cryptographicallystrong encryption key.

Referring again to FIG. 6, at 625, the first data is determined from theimage or audio signal at the second computing device. As previouslydescribed, the image or audio signal is a representation of first data.In other words, the password, and perhaps routing data and/or otheridentifying information may be recovered from the image or audio signalreceived, so that it may be further processed at the second computingdevice.

In some embodiments, the user of the second computing device may bepresented with an option (e.g. via a dialog box in a user interface) asto whether to continue with the remaining acts of method 600 (e.g. toperform a key exchange with the first computing device at 630). Thisoption may be provided to the user of the second computing device toconfirm that the key exchange (acts 628 to 645) should be performed. Forexample, where the user of the first computing device may be invitingthe user of the second computing device to join a group, and where itwould be prudent to warn the user of the second computing device thathis or her device may be subject to certain controls if he or she agreesto join the group, it may be desirable to give him or her the option ofdeclining the key exchange. Where an option is presented to the user ofthe second computing device and the user decides not to continue withthe key exchange, remaining acts of method 600 are not performed.

Alternatively, the key exchange may be performed automatically once theuser has activated a device (e.g. camera or microphone) to capture theimage or audio signal (at 620).

In at least some embodiments, establishment of the communication channelis initiated by the second computing device, which contacts the firstcomputing device at 628. In establishing the communication channel withthe first computing device, routing data pre-stored on the secondcomputing device (e.g. in an address book) or routing data recoveredfrom the first data received at 620 may be used, for example.

In at least one embodiment, where the routing data associated with thefirst computing device may comprise a PIN associated with the firstcomputing device, the communication channel between the first and secondcomputing device may comprise a peer-to-peer channel such as aPIN-to-PIN channel.

A key exchange is performed between the first and second computingdevices (630, 640) over a communication channel established between thetwo computing devices (e.g. the communication channel established by thesecond computing device after contacting the first computing device asidentified by the routing data at 628, or some other communicationchannel) in accordance with a key exchange protocol. The key exchangemay involve exchanges of second data between the first and secondcomputing devices, in accordance with the key exchange protocol (e.g.data required to complete the key exchange, which may include forexample, the transfer of computed intermediate values in accordance withthe key exchange protocol).

Although act 628 is shown as a separate act in FIG. 6, in at least someembodiments, the initiation of the establishment of the communicationchannel at 628 may be an act performed as a part of the key exchangeperformed by the second computing device at 640. The communicationchannel may be established over, for example, a WAN network (e.g. theInternet), an Intranet, an 802.11 or Bluetooth link, which may beinsecure. As noted above, in one embodiment, the communication channelmay be a peer-to-peer channel such as a PIN-to-PIN channel.

As a result of the key exchange, an encryption key may be derived ateach of the first and second computing devices (635, 645).

Subsequent to the key exchange between the first and second computingdevices at 630 and 640, any further communication of data between thefirst computing device and the second computing device over an otherwiseinsecure communication channel may be secured using the encryption keyderived at each computing device at 635 and 645, or a session keyderived from that encryption key derived at each computing device.

The key exchange protocol performed at 630 and 640 may be acryptographic method for password-authenticated key agreement (e.g.cryptographic keys may be established by one or more parties based ontheir knowledge of a shared password).

Since the key exchange protocol performed at 630 and 640 is based on ashared password (i.e. password-authenticated key agreement) and thepassword is independent of the security parameters (e.g. public keys), akey exchange protocol based on public keys or hashes thereof (e.g.Secure Socket Layer/Transport Layer Security (SSL/TLS), Secure KeyExchange Mechanism (SKEME), Internet Key Exchange (IKE), etc.) need notbe utilized in at least one embodiment described herein.

In some embodiments, the key exchange protocol performed at 630 and 640may comprise the SPEKE protocol. The SPEKE protocol is one example of acryptographic method for password-authenticated key agreement, which onthe basis of a shared password, allows parties to derive the sameencryption key (i.e. a SPEKE established key) for sending secure andauthenticated communications to each other, over what may be anotherwise insecure communication channel. The SPEKE protocol may involvea password-authenticated Diffie-Hellman exchange, where the passwordforms the base or “generator” of the exchange.

In other embodiments, the key exchange protocol may comprise variants ofthe SPEKE protocol. In other embodiments, the key exchange protocol,which may be SPEKE or variants thereof, may be combined with othercompatible key exchange protocols to provide additional layers ofsecurity. Persons skilled in the art will appreciate that by using SPEKEor variants thereof, fewer data exchanges may be required to completethe key exchange when compared to the use of other protocols (e.g.SSLITLS).

Other examples of key exchange protocols based on a shared passwordwhich may be utilized include, for example, encrypted key exchange(EKE), password authenticated key exchange by juggling (J-PAKE) andPassword Derived Moduli (PDM) to name a few.

Optionally, at 650, where the first computing device (or a user thereof)wishes to transmit one or more security parameters (e.g. one or morepublic keys) to a second computing device (or a user thereof), the oneor more security parameters may be encrypted with the encryption keyderived at 635 or a session key derived from the encryption key derivedat 635. Accordingly, at 660 a, the one or more encrypted securityparameters may be transmitted from the first computing device to thesecond computing device. At 665 a, the one or more encrypted securityparameters may be received at the second computing device from the firstcomputing device. Upon receiving the one or more encrypted securityparameters from the first computing device, the second computing devicemay decrypt the one or more encrypted security parameters using theencryption key derived at 645 or a session key derived from theencryption key derived at 645 to retrieve the one or more securityparameters of the first computing device.

Optionally, at 655, where the second computing device (or a userthereof) wishes to transmit one or more security parameters (e.g. one ormore public keys) to a first computing device (or a user thereof), theone or more security parameters may be encrypted with the encryption keyderived at 645 or a session key derived from the encryption key derivedat 645. Accordingly, at 665 b, the one or more encrypted securityparameters may be transmitted from the second computing device to thefirst computing device. At 660 b, the one or more encrypted securityparameters may be received at the first computing device from the secondcomputing device. Upon receiving the one or more encrypted securityparameters from the second computing device, the first computing devicemay decrypt the one or more encrypted security parameters using theencryption key derived at 635 or a session key derived from theencryption key derived at 635 to retrieve the one or more securityparameters of the second computing device.

Persons skilled in the art will appreciate that in different situations,one or more security parameters may be transmitted from the firstcomputing device to the second computing device (e.g. acts 660 a and 665a are performed), from the second computing device (e.g. acts 660 b and665 b are performed) to the first computing device, or both ways (e.g.acts 660 a, 660 b, 665 a and 665 b are performed).

In some embodiments, the one or more security parameters may compriseone or more public keys associated with a user of either the firstcomputing device or the second computing device. As described previouslywith reference to FIG. 4, data signed using a private key of a privatekey/public key pair can only be verified using the corresponding publickey of the pair, and data encrypted using a public key of a privatekey/public key pair can only be decrypted using the correspondingprivate key of the pair.

For example, once the user of a first computing device has the publickey of the user of a second computing device, the user of the firstcomputing device may then send encrypted messages to the user of thesecond computing device. As a further example, once the user of a firstcomputing device is reasonably certain that his public key has beenreceived by the second computing device, the user of the first computingdevice may then digitally sign messages to be sent to the user of thesecond computing device.

Similarly, once the user of a second computing device has the public keyof the user of a first computing device, the user of the secondcomputing device may then send encrypted messages to the user of thefirst computing device. As a further example, once the user of a secondcomputing device is reasonably certain that his public key has beenreceived by the first computing device, the user of the second computingdevice may then digitally sign messages to be sent to the user of thefirst computing device.

Multiple public keys (and corresponding private keys) may be transmittedfrom the first computing device to the second computing device, from thesecond computing device to the first computing device, or both. Forexample, two public keys may be associated with the same user of a givencomputing device. A first public key may be usable to encrypt messagesto a user of the given computing device, and a second public key may beusable to verify digital signatures of messages digitally signed at thegiven computing device. Different public keys may be employed fordifferent purposes, and the one or more security parameters beingtransmitted from one computing device to another may comprise aplurality of said different public keys.

FIG. 7 is a flowchart illustrating at least one variant embodiment thatis similar to method 600 shown in FIG. 6. Generally, embodiments of themethod illustrated by the flowchart in FIG. 7 are similar to embodimentsof the method illustrated by the flowchart in FIG. 6, except that someacts of the key exchange protocol and the transmittal of securityparameters are intertwined, as described in further detail below. Byintertwining acts of the key exchange protocol and the transmittal ofsecurity parameters, this may provide an advantage of not requiring asmany communication passes in order to effect the exchange of securityparameters between the first and second computing devices.

In one variant embodiment, the security parameters are transmitted inunencrypted form. The present inventors recognized that where the one ormore security parameters to be transmitted comprises one or more publickeys, there would be no need to keep the data secret (and thereforeencrypt it) because it is already “public” information (i.e. anyone mayhave access to it). However, when one or more security parameters arereceived at a given computing device, it is still typically desirable toensure that the received security parameters are authentic. In thisvariant embodiment, although a key is derived at each computing devicein accordance with a key exchange protocol (e.g. the SPEKE protocol),this key is not used as an encryption key per se (as in method 600 ofFIG. 6), but is instead used as a key for deriving a value that may beverified in order to authenticate the security parameters beingexchanged.

Acts 705, 710, and 715 are analogous to acts 605, 610 and 615 of FIG. 6,respectively, and the reader is directed to the description of FIG. 6above for further details in respect of acts 705, 710, and 715.Similarly, acts 720, 725, and 728 are analogous to acts 620, 625, and628 of FIG. 6, respectively, and the reader is directed to thedescription of FIG. 6 above for further details in respect of acts 720,725, and 728.

A key exchange is performed between the first and second computingdevices (730, 740) over a communication channel established between thetwo computing devices (e.g. the communication channel established by thesecond computing device after contacting the first computing device asidentified by the routing data at 728, or some other communicationchannel) in accordance with a key exchange protocol. The key exchangemay involve exchanges of second data between the first and secondcomputing devices, in accordance with the key exchange protocol (e.g.data required to complete the key exchange, which may include forexample, the transfer of computed intermediate values in accordance withthe key exchange protocol). For ease of exposition, the acts of the keyexchange will be described in FIG. 7 with reference to the SPEKEprotocol, although it will be understood by persons skilled in the artthat other key exchange protocols might be employed in variantembodiments.

Although act 728 is shown as a separate act in FIG. 7, in at least someembodiments, the initiation of the establishment of the communicationchannel at 728 may be an act performed as a part of the key exchangeperformed by the second computing device at 740. The communicationchannel may be established over, for example, a WAN network (e.g. theInternet), an Intranet, an 802.11 or Bluetooth link. As previouslydescribed, in one embodiment, the communication channel may be apeer-to-peer channel such as a PIN-to-PIN channel.

At 732, one or more intermediate keys may be derived at the firstcomputing device using the password as part of the key exchangeprotocol. Similarly, at 742, one or more intermediate keys may bederived at the second computing device using the password as part of thekey exchange protocol. The one or more intermediate keys derived usingthe password may be, for example, a SPEKE private key/public key pairwhere the key exchange protocol performed at 730 and 740 is the SPEKEprotocol.

At 744, an intermediate key derived at the second computing device (e.g.a SPEKE public key) is transmitted from the second computing device tothe first computing device, where it is received at 734. Where thesecond computing device (or a user thereof) wishes to transmit one ormore security parameters (e.g. one or more public keys associated with auser of the second computing device and intended for subsequent use inencoding messages) to a first computing device (or a user thereof), theone or more security parameters may also be transmitted from the secondcomputing device to the first computing device, at 744, where it isreceived, at 734.

At 736, a further key may be derived at the first computing device inaccordance with the key exchange protocol. This further key may be, forexample, a SPEKE established key, where the key exchange protocolperformed at 730 and 740 is the SPEKE protocol. As is known, the SPEKEestablished key derived at the first computing device is a function ofthe SPEKE public key derived at the second computing device, which isreceived from the second computing device at 734, and the SPEKE privatekey derived at the first computing device at 732.

At 738, a confirmation value is derived at the first computing deviceusing the key derived at 736 (e.g. SPEKE established key). Theconfirmation value may be a Keyed-Hash Message Authentication Code(HMAC), for example, which uses the key derived at 736 and a hashcomputed using at least some of the data exchanged (or to be exchanged)with the second computing device.

For example, at 738, an HMAC may be computed at the first computingdevice using the key derived at 736, and a hash computed based on thefollowing data:

-   -   at least some of the first data transmitted to the second        computing device at 715 (e.g. a group name, group type,        invitation ID, a PIN associated with the first computing        device), although the password need not be included in the        hashed data;    -   one or more security parameters (e.g. one or more public keys        for message encoding) received from the second computing device        at 734; and    -   one or more security parameters (e.g. one or more public keys        for message encoding) to be transmitted from the first computing        device to the second computing device at 750.        Those skilled in the art will appreciate that the data included        in the hash may not include all of the information identified        above, and may include additional data not identified above.        Generally, the confirmation value derived at the first computing        device may be derived as an HMAC computed by hashing all of the        data exchanged in the protocol, in combination with the SPEKE        established key derived at the first computing device.

At 750, an intermediate key derived at the first computing device at 732(e.g. a SPEKE public key) is transmitted from the first computing deviceto the second computing device, where it is received at 746. Where thefirst computing device (or a user thereof) wishes to transmit one ormore security parameters (e.g. one or more public keys associated with auser of the first computing device and intended for subsequent use inencoding messages) to a second computing device (or a user thereof), theone or more security parameters may also be transmitted from the firstcomputing device to the second computing device, at 750, where it isreceived, at 746. Additionally, at 750, the confirmation value may alsobe transmitted from the first computing device to the second computingdevice, where it is received at 746.

At 748, a further key may be derived at the second computing device inaccordance with the key exchange protocol. This further key may be, forexample, a SPEKE established key, where the key exchange protocolperformed at 730 and 740 is the SPEKE protocol. In accordance withSPEKE, the SPEKE established key derived at the first computing deviceat 736, and the SPEKE established key derived at the second computingdevice at 748, are expected to match.

At 754, a confirmation value is derived at the second computing deviceusing the key derived at 748 (e.g. SPEKE established key). Similar toact 738 performed at the first computing device, the confirmation valuemay be an HMAC, for example, computed using the key derived at 748 and ahash computed using at least some of the data exchanged (or to beexchanged) with the first computing device.

For example, at 754, an HMAC may be computed at the second computingdevice using the key derived at 748, and a hash computed based on thefollowing data:

-   -   at least some of the first data received from the first        computing device at 720 (e.g. a group name, group type,        invitation ID, a PIN associated with the first computing        device), although the password need not be included in the        hashed data;    -   one or more security parameters (e.g. one or more public keys        for message encoding) transmitted to the first computing device        at 744; and    -   one or more security parameters (e.g. one or more public keys        for message encoding) received from the first computing device        at 746.        Those skilled in the art will appreciate that the data included        in the hash may not include all of the information identified        above, and may include additional data not identified above.        Generally, the confirmation value derived at the second        computing device may be derived as an HMAC computed by hashing        all of the data exchanged in the protocol, in combination with        the SPEKE established key derived at the second computing        device.

At 756, the confirmation value derived at 754 may be transmitted fromthe second computing device to the first computing device, where it isreceived at 752.

At 758 and 760, the confirmation value received at each of the first andsecond computing devices is verified at the respective computing device.If the confirmation value received is successfully verified at a givencomputing device (i.e. it is confirmed that the value is what it isexpected to be, given that both computing devices know how the variousconfirmation values are computed), then the security parameters (e.g.one or more public keys used for message encoding) received at thatgiven computing device from the other computing device may be consideredto be authentic. If the confirmation value does not successfully verify(e.g. an HMAC will not be calculated accurately if the exchanged datahas been tampered with in transit), then the security parameters willfail to be authenticated.

In at least some embodiments, the confirmation value derived at thefirst computing device and the confirmation value derived at the secondcomputing device are computed so that they are different. This is doneintentionally by introducing known values in the computation of theconfirmation values (e.g. HMACs), and may provide added security bypreventing replay attacks where the second computing device (i.e. thejoiner) might simply re-transmit a confirmation value computed at andreceived from the first computing device (i.e. the inviter). Forexample, the hash used to derive the confirmation value at the firstcomputing device, at 738, may additionally be based on data thatcomprises a specific known value (e.g. the byte 0x03). Similarly, thehash used to derive the confirmation value at the second computingdevice, at 754, may additionally be based on data that comprises aspecific, but different known value (e.g. the byte 0x02). Accordingly,the confirmation value derived at the first computing device may be anHMAC computed based on all exchanged data plus a specific known valueassociated with the first computing device, using the SPEKE establishedkey derived at the first computing device. Similarly, the confirmationvalue derived at the second computing device may be an HMAC computedbased on all exchanged data plus a different, specific known valueassociated with the second computing device, and using the SPEKEestablished key derived at the second computing device. Although theconfirmation values derived at each of the computing devices will bedifferent, since the hash is additionally based on known values, theconfirmation values can still be verified at both computing devices.

Although the method 700 illustrated in FIG. 7 is described above withreference to the SPEKE protocol as the key exchange protocol, personsskilled in the art will appreciate that variants of SPEKE and other keyexchange protocols based on a shared password may also be utilized.

Persons skilled in the art will understand that method 700 may bemodified to accommodate situations where only one of the first andsecond computing devices transmits one or more security parameters tothe other of the first and second computing devices, in variantembodiments.

As previously noted, persons skilled in the art will also appreciatethat more than one security parameter may be transmitted in accordancewith the embodiments described herein. Furthermore, the one or moresecurity parameters are not limited to public keys, and may comprise,for example, other data which could then be used to provide authenticityand confidentiality for further communication between the two computingdevices. In some embodiments, multiple public keys may be transmitted inaccordance with the embodiments described herein, with a differentpublic key for a specific purpose. For example, the one or more publickeys may comprise a first public key usable to encrypt messages to auser of the first computing device, and a second public key usable toverify digital signatures of messages digitally signed at the firstcomputing device.

The embodiments described herein do not require a public keyinfrastructure in order to allow users of computing devices to transmitpublic keys to, and receive public keys from, each other.

The embodiments described herein also do not require manual verificationof a public key (e.g. a user checking and confirming the public keyfingerprint), which may require extensive user involvement.

Also, when the computing devices in the embodiments described above aremobile devices, since mobile devices are generally portable handhelddevices which can easily be brought physically close to one another,there may be more instances when users of mobile devices may want toexchange public keys or other security parameters on the spur of themoment (e.g. if two users, previously unknown to each other, meet at aparty or some other setting), in accordance with one or more embodimentsdescribed herein.

Although the embodiments described herein relate to the transmission andreception of an image or audio signal that is a representation of firstdata, in variant embodiments, first data may be transmitted in anelectronic mail (i.e. e-mail) message. In these embodiments, the firstdata may be transmitted as an e-mail message with the password containedin the message itself. In variant embodiments, the first data may betransmitted as an e-mail message with a hint to a password. Where a hintfor the password is contained in the message, the users of the twocomputing devices who wish to exchange security parameters should know apriori what the password may be, with the hint of the password providinga suggestion to the user of the second computing device as to what thepassword is. The user of the second computing device may then manuallyenter the password in a user interface of an application or confirm thatthe password is to be used in order to initiate the security parametertransmittal process on his or her computing device. In variantembodiments, the first data may be transmitted in a peer-to-peermessage, such as a PIN message, in a similar manner.

In variant embodiments, the first data transmitted from the first deviceto the second computing device (e.g. 615 of FIG. 6, 715 of FIG. 7), maybe transmitted in the form of a medium other than an image or audiosignal. For example, the first data may be transmitted in the form of aninfrared signal, to be received at the receiving computing device usingappropriate hardware.

The acts of method 600 of transmitting security parameters in accordancewith an embodiment described herein may be provided as executablesoftware instructions stored on computer-readable storage media.

The acts of method 600 of transmitting security parameters in accordancewith an embodiment described herein may be provided as executablesoftware instructions stored on transmission-type media.

By way of illustration, FIGS. 8 to 10 are example screen captures of adisplay (e.g. display 110 of FIG. 1) of the first computing device (e.g.mobile device 100 of FIG. 1) as a method of transmitting securityparameters (e.g. method 600 of FIG. 6 or method 700 of FIG. 7) isperformed in accordance with an example embodiment.

FIG. 8 is an example screen capture 800 of the display of the firstcomputing device prompting a user with an option to generate either animage (e.g. a barcode) or an e-mail message (e.g. act 610 of FIG. 6 oract 710 of FIG. 7). For example, in the user interface 800, the user mayselect a first option 810, “Show them a barcode”, to generate an image(e.g. a barcode), or a second option 820, “Send them a message”.

FIG. 9 is an example screen capture 900 of the display of the firstcomputing device wherein a user has selected an option to generate animage (e.g. a barcode). For example, a user of the first computingdevice may provide instructional text 910 and/or instructional diagrams920 to instruct a user to transmit the image (e.g. a barcode) from thefirst computing device to the second computing device.

FIG. 10 is an example screen capture 1000 of the display of the firstcomputing device as it displays an image (e.g. a barcode) 1010 fortransmission to the second computing device (see e.g. act 615 of FIG. 6or act 715 of FIG. 7).

By way of further illustration, FIGS. 11 to 13 are example screencaptures of a display (e.g. display 110 of FIG. 1) of the secondcomputing device (e.g. mobile device 100 of FIG. 1) as a method oftransmitting security parameters (e.g. method 600 of FIG. 6 or method700 of FIG. 7) is performed in accordance with an example embodiment.

FIG. 11 is an example screen capture 1100 of the display of the secondcomputing device prompting a user with an option to receive thetransmission of an image (e.g. a barcode) from the first computingdevice (see e.g. act 620 of FIG. 6 or act 720 of FIG. 7). For example,in a user interface of the second computing device, the user may selectan option 1110, “Join a group by scanning a barcode”, to begin receivingthe image (e.g. a barcode).

FIG. 12 is an example screen capture 1200 of the display of the secondcomputing device as it instructs a user on how to receive an image (e.g.a barcode) from the first computing device. For example, a userinterface of the second computing device may provide instructional text1210 and/or instructional diagrams 1220 to instruct a user on how toreceive the image from the first computing device at the secondcomputing device.

FIG. 13 is an example screen capture 1300 of the display of the secondcomputing device upon receiving an image (e.g. a barcode) transmittedfrom the first computing device, and upon determining first data fromthe image, such as a barcode for example (see e.g. act 625 of FIG. 6 oract 725 of FIG. 7). For example, a user interface of the secondcomputing device may provide a prompt 1310 to a user to confirm whetherto continue with the key exchange. The prompt may show the routing dataassociated with the first computing device (e.g. a PIN associated withthe first computing device). The prompt may also show other identifyinginformation of the first computing device or a user thereof (e.g. thatthe user of the first computing device is a member of the Work group“Group C”). Where the user wishes to continue, the user may indicatehis/her acceptance by selecting a confirmation option 1320, “JoinGroup”, for example. This may allow the user to communicate with othermembers who have joined the group securely, using the securityparameter(s) to be exchanged. Where the user does not wish to continuewith the remaining acts of method 600 or method 700, the user may abortby selecting a cancellation option 1330, “Cancel”, for example.

By way of further illustration, FIG. 14 is an example screen capture1400 of a display of the first computing device wherein a user hasselected an option to generate a message, instead of an image or audiosignal, in accordance with a variant embodiment previously describedherein. For example, in a user interface of the first computing device,the user of the first computing device may be prompted to enter in atext field 1410 either the name, email address or PIN, for example, ofthe second computing device or a user thereof. The user of the firstcomputing device may be prompted to enter in a text field 1420 thepassword itself and/or a hint for the password in a text field 1430. Ane-mail message or PIN message or other types of message addressed to auser of the second computing device may then be sent (e.g. in responsethe user of the first computing device selecting a send option 1440,“Send invitation”).

It will be understood that while examples have been presented hereinillustrating embodiments of a method where two computing devices areinvolved, more than two computing devices may be involved in variantimplementations. For example, a user may invite multiple people to joina private group, so that everyone in the private group can communicatewith each other. To facilitate this, the same barcode may be shown tomultiple invitees, or a different barcode may be shown to each invitee.

As used herein, the wording “and/or” is intended to represent aninclusive-or. That is, “X and/or Y” is intended to mean X or Y or both.Moreover, “X, Y, and/or Z” is intended to mean X or Y or Z or anycombination thereof.

A number of embodiments have been described herein. However, it will beunderstood by persons skilled in the art that other variants andmodifications may be made without departing from the scope of theclaimed embodiments appended hereto.

1. A method of transmitting one or more security parameters from a firstcomputing device to a second computing device, the method beingperformed at the first computing device, the method comprising:generating an image or audio signal for transmission to the secondcomputing device, wherein the image or audio signal is a representationof first data, the first data comprising a password, wherein thepassword is not derived from the one or more security parameters;transmitting the image or audio signal to the second computing device atwhich the password is determinable from the image or audio signal,respectively; and performing a key exchange with the second computingdevice over a communication channel between the first and secondcomputing devices, wherein second data is exchanged between the firstand second computing devices in accordance with a key exchange protocol,such that a key is derived at each of the first and second computingdevices using the password, and the one or more security parameters istransmitted to the second computing device during the key exchange suchthat secure communication between the first and second computing devicesis facilitated.
 2. The method of claim 1, wherein the first data furthercomprises routing data associated with the first computing device. 3.The method of claim 2, wherein the routing data associated with thefirst computing device comprises a PIN associated with the firstcomputing device, and the communication channel between the first andsecond computing devices comprises a PIN-to-PIN channel.
 4. The methodof claim 1, wherein the one or more security parameters comprise one ormore public keys stored on the first computing device.
 5. The method ofclaim 1, wherein transmitting the image or audio signal to the secondcomputing device is performed when the first and second computingdevices are in close physical proximity.
 6. The method of claim 1,wherein the key exchange protocol comprises a SPEKE protocol.
 7. Themethod of claim 1, wherein the audio signal comprises a plurality ofaudio tones.
 8. The method of claim 1, wherein at the transmitting, theaudio signal is transmitted via a speaker of the first computing device.9. The method of claim 1, wherein at the transmitting, the audio signalis transmitted via a channel established during a phone call between thefirst computing device and the second computing device.
 10. The methodof claim 1, further comprising generating the password, wherein thepassword is generated as a random number or string.
 11. The method ofclaim 10, wherein the password is generated for a single instance ofgenerating the image or audio signal.
 12. The method of claim 1, furthercomprising receiving one or more second security parameters from thesecond computing device, receiving a confirmation value from the secondcomputing device, and verifying the confirmation value.
 13. The methodof claim 1, wherein the image comprises a barcode, and transmitting theimage comprises displaying the image on a display of the first computingdevice.
 14. The method of claim 1, wherein the image is displayed by thefirst computing device and readable via a camera on the second computingdevice.
 15. The method of claim 1, wherein at the transmitting, theimage is transmitted via a display of the first computing device.
 16. Afirst computing device comprising a processor and a memory, theprocessor configured to perform a method of transmitting one or moresecurity parameters to a second computing device by executing one ormore application modules, said one or more application modulescomprising: a module configured to generate an image or audio signal fortransmission to the second computing device, wherein the image or audiosignal is a representation of first data, the first data comprising apassword, wherein the password is not derived from the one or moresecurity parameters; a module configured to transmit the image or audiosignal to the second computing device at which the password isdeterminable from the image or audio signal, respectively; and a moduleconfigured to perform a key exchange with the second computing deviceover a communication channel between the first and second computingdevices, wherein second data is exchanged between the first and secondcomputing devices in accordance with a key exchange protocol, such thata key is derived at each of the first and second computing devices usingthe password, and wherein the one or more security parameters istransmitted to the second computing device during the key exchange suchthat secure communication between the first and second computing devicesis facilitated.
 17. The first computing device of claim 16, wherein theone or more security parameters comprise one or more public keys storedon the first computing device.
 18. The first computing device of claim16, wherein the first data further comprises routing data.
 19. The firstcomputing device of claim 16, wherein transmitting the image comprisesdisplaying the image on a display of the first computing device.
 20. Anon-transitory computer readable storage medium comprising instructionsthat, when executed by a processor of a first computing device, causethe first computing device to perform acts of a method of transmittingone or more security parameters to a second computing device, the methodperformed at the first computing device, the acts comprising: generatingan image or audio signal for transmission to the second computingdevice, wherein the image or audio signal is a representation of firstdata, the first data comprising a password, wherein the password is notderived from the one or more security parameters; transmitting the imageor audio signal to the second computing device at which the password isdeterminable from the image or audio signal, respectively; andperforming a key exchange with the second computing device over acommunication channel between the first and second computing devices,wherein second data is exchanged between the first and second computingdevices in accordance with a key exchange protocol, such that a key isderived at each of the first and second computing devices using thepassword, and wherein the one or more security parameters is transmittedto the second computing device during the key exchange such that securecommunication between the first and second computing devices isfacilitated.